Vacuum power clutch



J. H. K: MFCOLLUM El AL Filed Dec. 20, 1930 I s Sheets-Sheet 2 o & O 6%.. .N w 1 ll. Y a !/l/I \M M :0 fi u M m r lfl n N m I O mn 0% U; 9

p J. H. K. M COLLUM ET AL 2,129,358

- VACUUM POWER CLUTCH Filed Dec. 20, 1930' '5 Sheets-Sheet 5 mew 12' James H. h. McCollurgz Henrz J DeM McC'o/zum ATTORNEY tion applied thereto, parts Patented Sept. 6, 1938 VACUUM POWER CLUTCH- James Harry Keighley McCollum and Henry John De Neville McCollum, Long Branch, N. J., assignors to A. Parker-Smith, New York,

N. Y. as trustee Application December 20, 1930, Serial- N0.'503,768

' 16- Claims. (Cl. 192-.01) I Fig. 20 is an end view of the mixture tube and Our invention relates to improvements in vacuum power clutches and the objects of our improvements are, first, to provide a thoroughly reliable mechanism which automatically engages and dis-engages the clutch, second, to provide a mechanism which automatically causes the motor vehicle to free-wheel or coast whenever the foot pressure is removed from the accelerator.

The best form of apparatus at present known to us embodying our invention, together with sundry modifications thereof, are illustrated in the accompanying three sheets of drawings in which:

Fig. 1 is a side elevation and partial section, with parts broken away, showing a clutch-actuating, double-acting, vacuum-operated servo-motor, with our invention applied thereto. v i

Fig. 2 is a section taken on irregular line 2 of Fig. 1.

Figs 3 and 4 are detailperspective views of twin valve port casings, and 1 Fig. 5 is a face view of another valve port casing.

Fig. 6 is a vertical section of part of another carburetor with modified forms 01 valve port casings for a double-acting servo-motor;

Fig. 7 is a side elevation of the upper portion of the carburetor shown in Fig. 6, with a valve port casing removed;

Fig. 8 is a detail face view of such casing;

Fig. 9 is a horizontal section on line 9--9 of i Fig. 10 is an elevation of the other side of the carburetor with the valve port casing on that side removed, and

Fig. 11 is a face view of such second port casing. 1

Figs. 12, '13 and 14 are enlarged detail cross sections of a two-way .cut-ofl. valve which is shown in three different positions.

Fig. 15 is a longitudinal section, and

Fig. 16 a cross section of a dual cut-oil valve of such type.

Fig 17 is a side elevation of a single-acting, vacuum-operated, servo-motor with my invenbeing shown in section and others broken away.

Fig. 18 is a vertical section of the upper portion of the mixture conduit for a carburetor having a rectangular internal cross section, with walls curved around the-throttle valve and ports for operating a single-acting servo-motor;

Fig. 19 is a similar view of acarburetor of this type with ports for operating a double-acting servo-motor; and

its flange, with other parts removed.

Fig. 21 is a cross section of a carburetor having'a cylindrical mixture conduit and a circular throttle valve, and l I Fig. 22 is a vertical section of the upper portion of the mixture conduit'of a carburetor of circular internal cross section embodying our invention and having a circular butterfly throttle valve cooperating with a special form of idling jet apparatus, said carburetor having a single port for operating a single-acting vacuum servomotor. Throughout the drawings like reference characters indicate like parts.

Referring to Figs. 1 to 5, a common form of clutch pedal I is thereshown'connected to the piston 2 of a double-acting, vacuum-operated, servo-motor comprising a. cylinder 5 pivotally supported at its left-hand end by lug 8 pivoted at 9'to a pedestal I set on a portion of the chassis 6, and at the other end by the piston rod passing through gland 3 in cylinder head 4 and having its free end pivoted to said clutch pedal. The left-hand end of cylinder 5 is connected by flexible conduit l3 to the casing 2| for port II inthe left-hand side wall of the mixture conduit 10 of a carburetor having the usual butterfly throttle valve I1 of slightly elliptical outline mounted on shaft and opening by turning in the direction of the arrow I 8. Whenever said throttle valve is turned in a counterclockwise direction for closing it, such move- 'ment will be stoppedin position for idling the engine when stop-arm 58 strikes stop-rib 60. From the right-hand end of cylinder 5 extends a similar conduit l4, branched at its other end to connect with the twin port-casings 22, 22', which cover twin ports l2, l2 ilLthe right-hahd side wall of said mixture conduit. These ports and port casings l2 and 22 are thus made double to straddle the idling jet apparatus 19.

Each of the conduitsv i3 and I4 is preferably provided with a two-way shut-oil valve I5, or [6, of a common type illustrated in Figs. 12, 13 and 14 as each comprising a valve plug 23 bored to form passages at right angles one to another which may register either with both sections of the connecting conduit .(as I4), or with one of said sections and the casing port 66 open to the atmosphere. IWhen this valve plug 23 is rotated within the 90 degree limits fixed by stop screw v cooperating with quadrant slot 24 cut in its circumference, as by means of a crank such as 63 (Fig. 1) having a perforated crank pin 84 in which a Bowden wire may be clamped by setscrew 85, the ends of cylinder 5 may be connected either with carburetor ports and i2 (Fig. 12) or with the atmosphere (Fig. 14) or closed completely .(Fig. 13).

As shown in Figs. 15 and 16 the two valves l5 and 16 may be combined in one, the casingSl of which is connected to both conduits l3 and i4 and mounted on the instrument board or dash 21 of the motor car. 'Ajquadr'ant slot 28 in the plug 26 of this dual valve again cooperates with a stop screw to limit the turning of the valve, which may t e-manipulated by knurled head 62.

r The carburetor shown in Figs. 6 to 11 is similar tothat shown in Figs. 1 and 2 except that it has another form of port casings and bearing surfaces therefor, andalso has a different kind of an idling jet apparatus l9, set in a circular port 55 bored in the wall of the carburetor back of the port i2.

In Fig. 17, the cylinder 29 of the single-acting servo-motor is open to the atmosphere at its righthand end through the ports 39, 39 in the cylinder head which merely serves as a guide for the piston rod 3|, the free end of which is pivoted to the clutch pedal 32. The other end of cylinder 29- is connected by conduit 38 to the port casing 36 on the carburetor mixture conduit 33 bolted over F the port 34 which cooperates with the throttle valve 35, as do the ports marked H in Figs. 1 and 6. As the servo-motor shown in Fig. 17 is singleacting, a spring, conventionally shown at 5B, is needed to close the clutch, while, with the doubleacti'ng servo-motor shown in Fig. 1, such spring might be dispensed with, though, of course, the regular clutch springs (not shown) would usually be retained. In Fig. 1 the piston 2 is equipped with oppositely disposed packing leathers, as shown,'to enable it to have an airtight fit with the cylinderwallsagainst suction in either direction, while piston 30 in Fig. 17 requires only one such packing leather, as there shown. In this figure, represents a modified form of idling jet apparatus differing .from that at [9 shown in Figs. 1 and-6a j In a1l..0f the forms of the invention above described, the initial movement of the throttle valve l1 begins to open it so as to permit the more rapid passage of combustible mixture to the motor, thereby accelerating the latter, the mixture conduit having the usual cylindrical cross section, and the valve i=1 having a cooperating, slightly elliptical outline, but in Figs. 18 and 19 the mixture conduit 50 has a rectangular cross section, as shown at 56 in Fig. 20, and the side walls of the conduit are curved about the ports as shown at 59, 59,so that the throttle valve H (which is rectangular inplan outline) does not'o'pen the passage 45 till after it has crossed either port .43 (Fig, 19) or-l5 :(Figa18) which'respectively communicates with conduit i3 or 35. Similarly, valve 4i opens port, and/or the smaller port'51 (Fig.

19), both of-which latter communicate with conduit ll (Fig. 1) before the passageway 45 through the mixture conduit 1" is opened by the movement'of said valve.- -The chamber I shown in broken lines as being back of the section plane in Fig. 19 allows air to pass from conduit it to either or both of said ports 44 and 51', aswell' as to the idling Jet port 58, when any one or more of them is subjected to suction from the intake manifold. Fuel 'lisfsupplied to the idler, indicated generally at 42, from the usual idling well I42, through the small'port at the upper end thereof which opens into the said idler apparatus 42. Consequently the usual mixture of air and fuel maybe discharged through idler jet port 58 .is gradually opened into the carburetor when throttle valve II is in '21, instead of the usual slightly'elliptical shape.

Such a valve wmcooperate with the ports 41 and 48 for operating a double-acting servo-motor such as shown in Fig. 1, and as the circular throttle valve gives only a very small opening for the passage of the combustible mixture on its initial movement, as compared with the elliptical valve, the opening and closing'cf ports 41 and 48 can be effected by this circular valve without materially changing the speed of the motor. Consequently, the result obtained with the curved walls 59 shown in Figs. 18 and 19 is also secured with this cheaper construction. Idling is effected in this construction by the flow of a small amount of the regular combustible mixture through the by-pass 50 around the completely closed throttle 49, the amount'of such mixture so deliveredbeing adjusted by the needle valve 5i held in adjusted position by lock nut 52.

When the carburetor throttle is in the idling position shown in Fig. 1, atmospheric pressure is in cylinder 5 on the right hand side of piston 2 and the full manifold vacuum is in the cylinder 5 on the left hand side of the piston 2 so that theclutch 'is fully disengaged. When the carburetor throttle I1 ismovedln the, direction indicated by arrow la, the intake manifold vacuum changes its action from the left hand end of cylinder 5 to the right hand end of cylinder '5 so that the pressure on the right hand side tween the left hand end of said cylinder 5 and piston 2 is practically that of the outside atmosphere, so that the engagement of the clutch will be as rapid as desirable, as the throttle I! by being moved in the direction of the arrow IS, the pressure in the right hand end of the cylinder will be always less than the pressure in the left hand end of the cylinder until the throttle i1 is wide open when the pressure in 'both ends of the cylinder 5 will be the same. When the throttle valve is in the idling position shown in Fig. 1, the port II will be between the throttle valve and the engine and the port i 2 will be between the throttle valve manner when desired. The valves l5 and It can be used to partiallythrottle the passageways connecting the ports H and I2 with the cylinder 5 to give .de'sirablespeed of'disengagement and engagement of thelclutch. The arrangement shown in Figs. 1, 2; 8; 4 and fi-isthat used when applyingthe mechanism to existing carburetors, such as we have done on our model D. A. Dodge automobile, which has a Stromberg carburetor. In commercial manufacture it will be more practical to arrange the. carburetor as shown in Figs.

6, 'I, 8, 9, l0 and- 11, with flanges on the outside of the carburetor barrel having flat surfaces to which the valve casings 2| and 22 will be bolted, as shown. The slot l2 in this case can be machined with a cutter, as can also be the slot ll.

Then-the hole 55 can be drilled, into which the idling apparatus I9 is inserted when the casing 22 is bolted in place and the passageways or pipes l3 and I4 are then connected to the port casings 2| and 22. The dual two-way valve shown in Fig. 15 attached to the dash board 2'! of the car can be used in place of the valves l5 and I6 and the carburetor ports II and I2 and cylinder 5 can be piped to the valve 26 shown in Fig. 15. As shown in Fig. 17 a single acting vacuum cylinder 29 and piston 30 and single carburetor port 34 piped by pipe 38 to'cylinder 29 can be used provided the spring 56 is made strong enough to overcome the-pull on the piston 30 due to the vacuum in the carburetor between the venturi and the engine. Figs. 18, 19 and 20 show a form of carburetor in which the throttle can be moved a certain amount without increasing the idling speed of the engine. This is designed for the purposeof allowing the clutch to be engaged with the engine idling and running the car at the speed at which the idling setting of the carburetor would run same. In Fig. 19 the port 51 and the port 44 are both connected to the space in the valve casing 22 which is connected by pipe l4 to the cylinder 5, the purpose of the port 51 which is small is to give a slow engagement of the clutch, the port 44 which is large causes a rapid engagement of the. clutch. With a little practice in connection with the form shown in- Fig. 1, fast clutch disengagement and varied speed of clutch engagement to suit all conditions of running can be easily obtained.

This vacuum power clutch mechanism, of course, causes the motor vehicle to free-wheel or coast whenever the pressure of the foot is removed from the. accelerator and allows the driver to use the left foot for the brake .and the right foot for the accelerator-55 when starting from a standstill on up grades or at any other time when such action is desirable. Among the ad vantages of the invention may be mentioned the simplification of, and reduction in number of parts required for use in, the combined control mechanism for adjusting the delivery of combustible mixture to the carburetor uptake l0, and of atmospheric or subatmospheric pressures to the conduit l3-or 38, variations in which pressures energize the vacuum-operated servo-motor which actuates the clutch-control lever I or 32. By the use of our present invention both .these functions are dominated by simple oscfllation of the valve shaft 20 (Figs. 1 and 2) about its axis. Consequently there is needed only a single, simple connection to the usual accelerator pedal (not shown) for so oscillating said shaft. This simplification results not only in economy-of first cost, but also renders the invention convenient in application to motor cars which may already have much other apparatus located under the engine hood; some of which might interfere with the installation of any separate chain of oper ative connections from the accelerator to'any other valve installed for controlling the varying degrees of pressure to be established in such conduit l3 or 38 from time to time for energizing the servo-motor; in addition to that already in use for controlling the carburetor throttle. When our present invention is used, such original carburetor control connection. from the accelerator performs adouble function, since it also controls the action of the servo-motor.

By way of analyzing the novel, basic principles of construction and operation of our invention, it may be observed that-it consists essentially in superimposing on, and combining with, the usual carburetor having a valve I1, 35, M, or 49, which is oscillatory about a fixed axis (that of shaft 20), additional means such as a port i I, 34, 43, or 41, and its connecting passages for controlling the degree of air pressure in a conduit (such as I3 or 3B) which is connected to the cylinder (such as 5 or 29) of a vacuum-energized servomotor whichautomatically actuates the clutch lever I or 32. Such port and passage means, being disposed in radial relation to the axis of shaft 20, can be operated by the same oscillations of the throttle valve that control the flow of combustible mixture to the carburetor uptake l0, either sequentially (as shown in Figs. 18 and The position of the parts shown in Figs. 1

and 17 is the position they will-be in with the parts set for idling but with the engine not running. Having now fully described our invention what we claim is;- t

1. In a vacuum power clutch mechanism, in

combination, a double-acting pneumatic power producing device, a carburetor having a throttle valve, and provided with ports in its casing cooperating with each edgeof said valve, together with a separate connection from each of said ports to one of two oppositely disposed portions of the interior of said power producing device; whereby said power producing device 'is controlled by motion of saidthrottle valve with reference to said ports.

2. In a vacuum power clutch mechanism, in

combination, a pneumatic power producing device, a carburetor having a throttle valve and ports, said pneumatic power producing device being controlled by the co-operation of said throttle valve and said ports. i

3. In a vacuum power clutch mechanism, in combination, a double-acting pneumatic power producing device, a carburetor having a throttle valve and ports, means for connecting said carburetor to 'said double-acting pneumatic power producing device, said pneumatic power producing device being controlled by the co-operation of said throttle valve and said ports.

4. In a vacuum power clutch mechanism, in combination, a pneumatic power producing device operable by variations of .vacuum therein, a carburetor having a throttle valve and ports, means for connecting said carburetorto said pneumatic power producing device, said pneumatic power producing device being controlled by the co-operation of said throttle valve and ports for producing rapid disengagement of and variable engagement of said clutch mechanism.

5 .In a vacuum power clutch mechanism, in combination, a double-acting pneumatic power producing device, a carburetor having a throttle valve and ports, a clutch actuating member,

means connecting said carburetor and said double-acting pneumatic power producinggde-.

vice, said double-acting pneumatic power producing device "being controlled by the co-operation of said throttle valve and said ports for producing rapid clutch disengaging movement'of and variable clutch engaging movement of said clutch actuating member.

6. In a vacuum power clutch mechanism, in combination a supporting frame, a double ended cylinder having-a double-acting piston, a clutch pedal connected to said piston by means ofia piston rod properly packed, a carburetor having a throttle valve and ports, one of said ports being connected to one end of said cylinder by suitable piping, the other of said ports being connected to the other end of said cylinder. by suitable piping, valves in said piping, said cylinder being suitably connected to said supporting frame, and said throttle valve and ports co-operating so as to control said double-acting piston.

7., In avacuumpower clutch mechanism, in combination, a clutch pedal, a cylinder and piston, a motor vehicle frame; a carburetor having a throttle valve and ports, piping connecting carburetor having a throttle valve and ports, said ports being connected by passageways to said pneumatic power producing device, and said pneumatic power producing device being controlled by the action of said throttle valve and ports. a

'9. In a vacuum-power clutch-operating mechanism comprising a clutch-actuating member, and a pneumatic power-producing device operatively connected to the said member, the com-- bination, with said abovedescribed apparatus, of a carburetor having a mixture conduitand a throttle valve mechanism for controlling the flow of air through saidconduit in which the wall of said conduit is provided with a port adjacent the edge ofsaid valve when the'latter is in closed position, and on that side of said valve edge toward which it moves when the valve opens, and a conduit-exterior of said valve, said throttle valve mechanism being provided with means for retarding the flow of gases through said mixture conduit until after said valve edge has moved across said port in said conduit wall.

10. In a vacuum-power, clutch-operating mechanism comprising a clutch-actuating member, and a pneumatic po-wer-producingdevice operatively connected to said member, the combination, with said above described apparatus, of a carburetor having a mixture conduit and a throttle valve controlling the flow of a combustible gaseous mixture therethrough, in which carburetor a wall of said conduit is provided with a valve port extending therethrough adjacent one edge of said throttle valve when the latter is in closed position, and located onthat side thereof toward which it moves when opened to permit a flow of said gaseous mixture through said conduit; said valve port being connected to amasus I the carburetor. on said frame andconnected to said lever, a

a said pneumatic power-producing device and the wall surface of said conduit adjacent said valve edgeI being curved to correspond to the. path of travel of said valve edge; whereby. said edge when opening will move across said port before said valve is opened to permit such flow of mixture through said conduit. r I

11. In a vacuum-power, clutch-operating mechanism comprising a clutch-actuating member, and a pneumatic power producing device operatively connected to said member, the combination, with said above described app ratus, of arcarburetor having a mixture conduit and a throttle valve mounted on an axis extending across a portion thereof intermediate of its opposite edges and across said conduit, the'walls of which latter are provided with a valve port adjacent one edge of saidval've when it is in closed position and located on that side of said edge toward which it must move to open said conduit to a flow of gaseous mixture through it past said valve, and an idling port located in said conduit walls adjacent the other edge of said valve and on the side thereof from which it will move away during suchthrottleopening; said above mentioned valve port being connected to said pneumatic power-producing device and'th'e inner wall of said mixture conduit having that pertion of its surface in which said first mentioned valve port is located so curved as to substantially conform to a surface which would be generated by the swinging of the adjacent curved edge of a the butterflysthrottle valve; whereby said port,

may be crossed by said valve edge without further increasing the areaof throttle opening in 12. The combination, with a vacuum-operated app ratus for actuating the clutch mechanism of a motor car, of a carburetor having a mixture conduit of rectangular cross section with a butterfly throttle valve of cooperating rectangular outline pivoted therein, the walls of said conduit adjacent the swinging ends ofsaid valve when it is closed each being curved to an arc of'the same radius as that of the adjacent valve end, and one of said curved wall sections having a portin its face connected tosaid vacuum-operated appa atus; whereby, whenever a valve end swings past said port, variations of air pressure are created in said vacuum operated apparatus without opening said throttle valves x 13. The combination, with a vacuum-operated servo-motor connected to the 'Gll1t0h mechanism of a motor car, of a carburetor for said car having a butterfly throttle valve,ga port in one wall adjacent one edge of said valve when the latter is closed which is connected to said servo-motor, and a port for an idling jet in its opposite wall adjacent the other edge of said valve when the latter is closed.

14. The combination, with the intake of a carburetor, a throttle valve for controlling the flow of combustible mixture to said intake which is oscillatory about a fixed axis. and a conduit in which varying degrees of air pressure are to be established fromtime to time, of 'means communicating with said intake and disposed'in cooperative valvular relation with said throttle valve for controlling the degree of pressure in such conduit, said meansbeing operative for such purpose during at least portions of the period of movement of said throttle valve and adapted to effect such changes in air pressure in said conduit sequentially with reference to 2,129,858 changes in the new of combustible mixture through said carburetor intake.

15. In an automobile having a carburetor controlled by an oscillatory throttle valve, an accelerator pedal, a clutch-actuating lever and a servo-motor for automatically operating the same,-

the combination, with said above described apparatus, of a member oscillatory about the axis 01' said valve operatively connected directly to said accelerator and adapted to control both the position of said throttle and all automatic movements of said servo-motor; whereby the use of separate control connections from said accelset said servo-motor in action before any open-v ing of said throttle valve is caused thereby.

16. In an automobile having a carburetor controlled by an oscillatory throttle valve, an accelerator pedal, 9. clutch-actuating lever and a servo-motor for automatically operating the same.

the combination, with said above described apparatus, of a member oscillatory about the axis of said valve operatively connected directly to said accelerator and adapted to control both the position of said throttle and all automatic movements of said servo-motor; whereby the use of separate control connections from said accel-. erator to said throttle and to said servo-motor may be dispensed with, said carburetor and servo-motor being so constructed and arranged that an initial movement of said member'will set said servo-motor in action before any opening of said throttle valve is caused thereby, while a reverse movement thereof will close said throttle valve before said servo-motor is set in action. i

JAMES HARRY KEIGHLEY MCCOLLUM. HENRY JOHN DE NEVILLE MCCOLLU'M. 

